Security protection system and method for network construction type energy storage power grid

Abstract

The invention relates to the technical field of intelligent power grid protection, and particularly discloses a safety protection system and method for a network-forming type energy storage power grid, and the system comprises a power grid state monitoring unit which collects the voltage, frequency, short-circuit capacity ratio (SCR), phase angle and other parameters of a grid-connected point in real time. And the cooperative control unit generates an operation mode control instruction and a power scheduling instruction based on the operation strategy model, and realizes switching between a network construction mode and a network following mode and primary frequency modulation, AGC and AVC power scheduling. When receiving an instruction or monitoring disturbance, the transient response execution unit performs inertia support, fault ride-through, oscillation suppression, black start support and other operations, and maintains voltage and frequency stable. And the digital intelligent security protection unit performs full-state monitoring on a physical environment, network information and an equipment operation state, and executes an active protection strategy to ensure safe, stable and reliable operation of the system. According to the invention, the safety, the stability and the reliability of the network-forming type energy storage power grid are effectively ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smart grid protection, in particular to a grid-constructed energy storage power grid safety protection system and method. BACKGROUND

[0002] With the increasing proportion of new energy power generation, energy storage systems are increasingly widely used in power systems, especially in grid-constructed energy storage power grids. Energy storage units can not only undertake energy regulation tasks, but also provide frequency and voltage support. However, due to the large fluctuation and strong intermittency of new energy power generation, grid-constructed energy storage power grids are prone to voltage fluctuations, frequency abnormalities and short-circuit capacity changes during grid-connected operation, which affects the stability and reliability of power grid operation.

[0003] At present, the traditional energy storage system control mainly relies on preset strategies and single-dimensional response, which is difficult to realize dynamic switching between grid-constructed mode and grid-following mode, as well as coordinated management of primary frequency regulation, automatic generation control (AGC), automatic voltage control (AVC) and other power dispatching instructions. At the same time, when power grid disturbance or abnormal event occurs, the transient response capability of the energy storage system is insufficient, which cannot quickly adjust the output power or operating mode, thereby reducing the dynamic stability of the grid-connected point. In addition, the safety protection of the grid-constructed energy storage system also has deficiencies, including physical environment safety, network information safety and equipment operation safety and other risks. The existing technology is difficult to monitor and actively protect the system in all states, which is easily affected by external attacks or internal faults, further restricting the reliable application of the energy storage system in the grid-constructed power grid.

[0004] Therefore, it is urgent to invent an intelligent safety protection technology for grid-constructed energy storage power grid to solve the problems that the existing energy storage system is difficult to realize dynamic mode switching, power dispatching coordination and multi-dimensional transient response in the grid-constructed power grid, and lacks comprehensive safety protection, resulting in insufficient system stability and reliability. SUMMARY

[0005] Therefore, the present application proposes a grid-constructed energy storage power grid safety protection system and method, which aims to solve the problem that the existing energy storage system is difficult to realize dynamic mode switching, power dispatching coordination and multi-dimensional transient response in the grid-constructed power grid, and lacks comprehensive safety protection, resulting in insufficient system stability and reliability.

[0006] The present application proposes a grid-constructed energy storage power grid safety protection system, which comprises:

[0007] A power grid state monitoring unit is configured to collect power grid operating parameters of a grid-constructed energy storage system grid-connected point in real time, wherein the power grid operating parameters include power grid voltage, power grid frequency, short-circuit capacity ratio SCR and phase angle.

[0008] The cooperative control unit is configured to receive grid operation parameters, and generate cooperative control instructions based on a preset Shaguo Barren New Energy Base operation strategy model, the cooperative control instructions including operation mode control instructions and power scheduling instructions; the operation mode control instructions are used to switch between the grid-connected mode and the grid-following mode, and the power scheduling instructions include primary frequency modulation instructions, automatic generation control (AGC) instructions, and automatic voltage control (AVC) instructions;

[0009] The transient response execution unit is configured to perform multi-dimensional transient response operations to maintain the stability of the grid-connected point voltage and frequency when the cooperative control instructions are received or the grid disturbance is monitored;

[0010] The digitalized security protection unit is configured to perform full-state monitoring and active protection on the physical environment security, network information security, and equipment operation security of the grid-connected energy storage system.

[0011] Further, when the cooperative control unit generates the operation mode control instructions, the following steps are included:

[0012] The cooperative control unit is further configured to preset a grid strength threshold value, wherein the grid strength threshold value is defined based on a short circuit capacity ratio (SCR);

[0013] When the real-time SCR value monitored by the grid state monitoring unit is lower than the grid strength threshold value, the cooperative control unit generates a control instruction to switch to the grid-connected mode;

[0014] When the real-time SCR value is higher than the grid strength threshold value, the cooperative control unit generates a control instruction to switch to the grid-following mode;

[0015] The cooperative control unit is further configured to perform an online switching function to ensure smooth power output transition during mode switching without grid disturbance.

[0016] Further, the transient response execution unit includes:

[0017] The inertia support module is configured to simulate the inertia response of a synchronous generator according to the grid frequency change rate monitored by the grid state monitoring unit, and provide virtual inertia support; the inertia time constant of the inertia support module is adjustable within a range of 0 seconds to 20 seconds;

[0018] The fault ride-through module is configured to perform grid support operations when the grid state monitoring unit monitors a sudden change in grid voltage or phase angle;

[0019] The oscillation suppression module is configured to output damping control power to suppress power oscillation when the grid state monitoring unit monitors the existence of power oscillation of a specific frequency in the grid;

[0020] The black start support module is configured to receive a black start instruction when a large-scale power failure accident occurs in a power grid, provide a voltage and frequency reference for the power grid and a new energy station in a specified region, and execute a recovery process of the regional power grid.

[0021] Further, the fault ride-through module includes the following operations when the power grid state monitoring unit detects a sudden change in the grid voltage or phase angle:

[0022] Low-voltage fault ride-through operation: when the grid point voltage is detected to drop to 0% to 90% of the rated voltage, the power conversion system PCS outputs reactive current within 10 milliseconds, and the reactive current fluctuation during low-voltage ride-through is less than 15%, the transient overvoltage caused after fault recovery is less than 10%, and the strong overload support capability is maintained for at least 10 seconds;

[0023] High-voltage fault ride-through operation: when the grid point voltage is detected to rise to 110% to 130% of the rated voltage, the active power output is maintained unchanged within the full battery state of charge SOC range, realizing transient decoupling control of active power and reactive power;

[0024] Phase angle jump ride-through operation: when a step jump in the grid point voltage phase angle is detected, the amplitude and phase angle of the machine terminal voltage are maintained stable, and active power is output to suppress the grid phase angle jump.

[0025] Further, the oscillation suppression module includes the following operations when the power grid state monitoring unit detects that the power grid has a power oscillation at a specific frequency:

[0026] The oscillation suppression module is further configured to perform fast Fourier transform on the active power signal collected by the power grid state monitoring unit in real time to determine whether there is a low-frequency oscillation component with a frequency in the range of 0.2 Hz to 2.5 Hz, wherein:

[0027] If the low-frequency oscillation component is identified and its amplitude exceeds a preset oscillation threshold, a modulated active power signal with a controlled amplitude opposite to the phase of the oscillation component is determined;

[0028] The oscillation suppression module is further configured to superimpose the modulated active power signal on the active component of the power dispatch instruction output by the cooperative control unit, and the maximum variation of the modulated active power signal based on the power conversion system PCS output to the power grid is in the range of 10% to 30% of the rated power of the energy storage system.

[0029] Further, the black start support module executes the recovery process of the regional power grid, including:

[0030] The black start support module is further configured to disconnect the connection with the main power grid and enter an island operation mode after receiving a black start authorization instruction from a power grid dispatching center;

[0031] The black start support module is further configured to control multiple power conversion systems PCS to operate in parallel, establish a stable voltage and frequency reference without external power grid support, and the number of PCS operating in parallel is not less than 10, and the maximum deviation of the effective value of the current output by each PCS when operating in parallel is not more than 5%.

[0032] The black start support module is further configured to provide power to the new energy station, the load in the substation or the synchronous generator in steps according to a preset black start path scheme configured by the black start support module.

[0033] Further, when the digital and intelligent security protection unit performs full-state monitoring and active protection on the physical environment security, network information security and equipment operation security of the grid-forming energy storage system, it includes:

[0034] The digital and intelligent security protection unit is further configured to collect environmental data of the location of the energy storage device, wherein the environmental data includes wind speed, dust concentration and temperature;

[0035] The digital and intelligent security protection unit is further configured to perform a linkage operation including adjusting the device heat dissipation strategy and reinforcing the external protection structure when the environmental data exceeds the preset safety threshold configured by the digital and intelligent security protection unit;

[0036] The digital and intelligent security protection unit is further configured to verify the localization information of the core hardware and software components of the grid-forming energy storage system, wherein the core hardware and software components include insulated gate bipolar transistors IGBT, control chips and operating systems;

[0037] The verification is based on an internally built self-controllable component database;

[0038] The digital and intelligent security protection unit is further configured to monitor the operating state of the energy storage system in the full state of charge SOC range, low short circuit capacity ratio and high voltage disturbance working condition, and execute an active control strategy to ensure that the active power does not decrease during high voltage ride-through, and to realize full-power stable operation under the condition of a weak power grid with a short circuit capacity ratio SCR of 1.1.

[0039] Further, when the digital and intelligent security protection unit performs full-state monitoring and active protection on the physical environment security, network information security and equipment operation security of the grid-forming energy storage system, it further includes:

[0040] The digital and intelligent security protection unit is further configured to monitor the internal state parameters of each battery pack in the energy storage system, including temperature, voltage and internal resistance;

[0041] The digital and intelligent safety protection unit is further configured to perform a fire suppression operation for the battery pack when the internal state parameter of any battery pack exceeds a fire warning threshold configured by the digital and intelligent safety protection unit.

[0042] Further, the digital and intelligent safety protection unit is further configured with an overload operation capability, and the overload operation capability is specifically:

[0043] When the 110% rated current working condition, the digital and intelligent safety protection unit determines not to adjust the operation time;

[0044] When the 120% rated current working condition, the digital and intelligent safety protection unit determines that the operation time is not less than 2 minutes;

[0045] When the transient state of the power grid occurs serious fault, the digital and intelligent safety protection unit has a short-time overload capability of outputting 300% rated current, and the operation time is 10 seconds.

[0046] Compared with the prior art, the beneficial effects of the present application are that: the grid state monitoring unit collects the key operating parameters of the grid-connected point of the grid-structured energy storage system in real time, including grid voltage, grid frequency, short circuit capacity ratio (SCR) and phase angle, etc. information, realizes the comprehensive grasp of the operation state of the grid, and provides accurate and real-time data basis for the operation and regulation of the energy storage system. Through continuous monitoring of the grid state, problems such as grid fluctuation, frequency anomaly or short circuit capacity change can be found in time, providing basis for subsequent collaborative control and transient response, so as to effectively avoid the regulation failure caused by information lag or inaccurate data. Secondly, the collaborative control unit can generate operation mode control instructions and power scheduling instructions based on the preset Shaguo Huang new energy base operation strategy model, realizing the dynamic switching between grid mode and follow grid mode. This switching not only meets the flexible demand under different grid operation conditions, but also coordinates the execution of primary frequency modulation instruction, automatic generation control (AGC) instruction and automatic voltage control (AVC) instruction, realizes multi-dimensional power scheduling collaborative management, significantly improves the regulation efficiency and grid support capability of the energy storage system, and effectively alleviates the instability factors brought by new energy generation fluctuation. At the same time, when the collaborative control instruction is received or the grid disturbance is monitored, the transient response execution unit can quickly execute multi-dimensional transient response operations such as power rapid adjustment, operation mode switching and local load regulation, so as to maintain the stability of the grid-connected point voltage and frequency. This rapid response capability can significantly improve the dynamic stability of the system when facing grid disturbance or sudden abnormal events, reduce the impact on the grid, and improve the adaptability of the energy storage unit to grid fluctuation. Finally, the digital security protection unit realizes the full-state monitoring and active protection of the physical environment safety, network information safety and equipment operation safety of the grid-structured energy storage system, effectively reducing the influence of external attacks or internal faults on the system operation. The unit can realize abnormal detection, intrusion warning, fault isolation and risk assessment of the key equipment of the energy storage system, ensure the long-term stable operation of the energy storage system, and provide reliable security protection for the grid.

[0047] In another aspect, the present application also provides a grid-structured energy storage grid safety protection method, comprising:

[0048] Real-time acquisition of grid operating parameters of the grid-connected point of the grid-structured energy storage system, the grid operating parameters including grid voltage, grid frequency, short circuit capacity ratio SCR and phase angle;

[0049] Receiving the grid operating parameters, and generating collaborative control instructions based on the preset Shaguo Huang new energy base operation strategy model, the collaborative control instructions including operation mode control instructions and power scheduling instructions; the operation mode control instructions are used for switching between grid mode and follow grid mode, and the power scheduling instructions include primary frequency modulation instruction, automatic generation control AGC instruction and automatic voltage control AVC instruction;

[0050] When receiving the cooperative control instruction or monitoring the power grid disturbance, a multi-dimensional transient response operation is performed to maintain the stability of the grid point voltage and frequency.

[0051] The physical environment safety, network information safety and device operation safety of the network-constructed energy storage system are monitored and actively protected in a full state.

[0052] It can be understood that the network-constructed energy storage grid safety protection system and method in each of the above embodiments of the present application have the same beneficial effects, which will not be repeated. BRIEF DESCRIPTION OF DRAWINGS

[0053] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the various drawings to designate identical parts. In the drawings:

[0054] Figure 1 A functional block diagram of a network-constructed energy storage grid safety protection system according to an embodiment of the present application is provided.

[0055] Figure 2 A flowchart of a network-constructed energy storage grid safety protection system according to an embodiment of the present application is provided.

[0056] Figure 3 A flowchart of a network-constructed energy storage grid safety protection method according to an embodiment of the present application is provided. DETAILED DESCRIPTION

[0057] Exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0058] As shown in Figures 1-2 In some embodiments of the present application, the present embodiment provides a network-constructed energy storage grid safety protection system, which comprises a grid state monitoring unit, a cooperative control unit, a transient response execution unit and a digitalized safety protection unit.

[0059] Specifically, the power grid state monitoring unit is configured to collect power grid operating parameters of the grid-connected point of the grid-constructed energy storage system in real time, the power grid operating parameters including power grid voltage, power grid frequency, short circuit capacity ratio (SCR), and phase angle; the collaborative control unit is configured to receive the power grid operating parameters, and generate collaborative control instructions based on a preset Shagehuang new energy base operating strategy model, the collaborative control instructions including operating mode control instructions and power scheduling instructions; the operating mode control instructions are configured to switch between the grid-constructed mode and the grid-followed mode, and the power scheduling instructions including primary frequency modulation instructions, automatic generation control (AGC) instructions, and automatic voltage control (AVC) instructions; the transient response execution unit is configured to execute multi-dimensional transient response operations to maintain the stability of the voltage and frequency of the grid-connected point when receiving the collaborative control instructions or monitoring power grid disturbances; and the digitized safety protection unit is configured to perform full-state monitoring and active protection on the physical environment safety, network information safety, and equipment operation safety of the grid-constructed energy storage system.

[0060] It can be understood that, by monitoring, controlling, responding, and protecting each key link of the grid-constructed energy storage grid, stable and safe operation of the system is achieved. The power grid state monitoring unit collects power grid voltage, power grid frequency, short circuit capacity ratio (SCR), and phase angle and other operating parameters of the grid-connected point in real time, providing accurate power grid state information for the system. These information not only reflects the real-time operation of the power grid, but also provides data basis for subsequent collaborative control and transient response, and is the basis for accurate regulation and control of the entire system. Secondly, the collaborative control unit generates collaborative control instructions based on the preset Shagehuang new energy base operating strategy model, including operating mode control instructions and power scheduling instructions. The operating mode control instructions are configured to dynamically switch between the grid-constructed mode and the grid-followed mode, enabling the energy storage system to flexibly adapt to different power grid operating environments; the power scheduling instructions include primary frequency modulation, automatic generation control (AGC), and automatic voltage control (AVC) instructions, achieving multi-dimensional collaborative management of the power output of the energy storage unit, thereby ensuring the stability of the power grid frequency and voltage. In addition, the transient response execution unit can quickly execute multi-dimensional transient response operations, including power regulation, mode switching, and local load regulation, when receiving the collaborative control instructions or monitoring power grid disturbances, to maintain the voltage and frequency stability of the grid-connected point. This fast response mechanism ensures that the energy storage system can quickly recover to stable operation when facing power grid disturbances or sudden abnormal events, improving the dynamic stability and anti-interference ability of the system. Finally, the digitized safety protection unit performs full-state monitoring and active protection on the physical environment, network information, and equipment operation safety, combined with risk assessment, intrusion detection, and fault isolation mechanisms, to ensure the safe and reliable operation of the energy storage system under various abnormal conditions. This comprehensive protection strategy, combined with collaborative control and transient response mechanisms, enables the system to achieve stable, safe, and efficient operation in complex power grid environments.

[0061] To be specific, the application provides a network-constructing energy storage power grid safety protection system, which comprises a power grid state monitoring unit, a collaborative control unit, a transient response execution unit and a digitized safety protection unit. The power grid state monitoring unit is used to collect power grid operation parameters of a network-constructing energy storage system in real time, including power grid voltage, power grid frequency, short circuit capacity ratio (SCR) and phase angle, etc. The power grid state monitoring unit transmits the collected parameters to the collaborative control unit in real time, providing accurate data basis for subsequent control and response. Secondly, the collaborative control unit receives the power grid operation parameters transmitted by the power grid state monitoring unit, and generates collaborative control instructions based on a preset Shaguo Huang new energy base operation strategy model. The collaborative control instructions include operation mode control instructions and power scheduling instructions, wherein the operation mode control instructions are used to dynamically switch between network-constructing mode and network-following mode; the power scheduling instructions include primary frequency modulation instructions, automatic generation control (AGC) instructions and automatic voltage control (AVC) instructions, which are used to coordinate the power output of the energy storage unit and realize the adjustment of power grid frequency and voltage. In addition, the transient response execution unit can quickly execute multi-dimensional transient response operations, including power rapid adjustment, operation mode switching and local load regulation, etc., when it receives the collaborative control instructions issued by the collaborative control unit or monitors power grid disturbances, so as to maintain the voltage and frequency stability of the network point and enhance the dynamic response capability and anti-disturbance capability of the system. Finally, the digitized safety protection unit is used to monitor and actively protect the physical environment safety, network information safety and equipment operation safety of the network-constructing energy storage system. This unit can realize abnormal detection, intrusion early warning, fault isolation and risk assessment of key equipment of the energy storage system, and take protective measures in time when internal faults or external attacks occur, so as to ensure the safe and reliable operation of the system in complex operating environment.

[0062] It can be seen that in the present embodiment, the power grid state monitoring unit, the collaborative control unit, the transient response execution unit and the digitized safety protection unit work collaboratively, and through real-time monitoring, intelligent control, rapid response and all-round protection, the network-constructing energy storage power grid is comprehensively improved in terms of operation stability, power regulation capability, dynamic response speed and system safety, etc.

[0063] Specifically, when the cooperative control unit generates the operation mode control instruction, the cooperative control unit is further configured to pre-set a grid strength threshold, wherein the grid strength threshold is defined based on the short circuit capacity ratio SCR; when the real-time SCR value monitored by the grid state monitoring unit is lower than the grid strength threshold, the cooperative control unit generates a control instruction to switch to the grid-forming mode; when the real-time SCR value is higher than the grid strength threshold, the cooperative control unit generates a control instruction to switch to the grid-following mode; and the cooperative control unit is further configured to perform an online switching function to ensure smooth transition of power output during mode switching and disturbance-free grid connection. It can be understood that the cooperative control unit realizes dynamic switching between the grid-forming mode and the grid-following mode by real-time judgment of the grid strength when generating the operation mode control instruction. To this end, the cooperative control unit pre-sets a grid strength threshold, which is defined based on the short circuit capacity ratio (SCR) and used to measure the grid capacity and stability of the grid connection point. When the real-time SCR value monitored by the grid state monitoring unit is lower than the pre-set grid strength threshold, it indicates that the grid capacity is insufficient or there are potential instability factors in the system, and the cooperative control unit generates a control instruction to switch to the grid-forming mode, so that the energy storage system operates independently from the main grid, thereby ensuring the safety and stability of the system. On the contrary, when the real-time SCR value is higher than the grid strength threshold, it indicates that the grid strength is sufficient and the system can safely accommodate the grid connection operation of the energy storage unit, and at this time the cooperative control unit generates a control instruction to switch to the grid-following mode, so that the energy storage system re-joins the grid, realizing the optimal utilization of electric energy and the stable support of the grid. Through this real-time judgment and control mechanism, the system can dynamically adjust the operation mode according to the grid strength, avoiding power regulation failure or grid disturbance caused by grid fluctuations or insufficient strength. In addition, the cooperative control unit also has an online switching function, which can realize smooth transition of power output during mode switching, avoiding sudden power fluctuations or grid disturbances during switching. This function realizes seamless switching between the grid-forming mode and the grid-following mode through continuous monitoring and adjustment of the output power of the energy storage unit, thereby ensuring stable operation of the system in a dynamic environment and safe support for the grid. In summary, through the pre-set grid strength threshold, real-time SCR monitoring and online switching function, intelligent mode switching and power smooth control of the energy storage system under different grid conditions are realized, thereby ensuring the safety, stability and reliability of the grid-forming energy storage grid.

[0064] It can be seen that in the embodiment, the cooperative control unit is used to generate operation mode control instructions according to the real-time power grid parameters collected by the power grid state monitoring unit, so as to realize dynamic switching between the grid-constructing mode and the grid-following mode. To this end, the cooperative control unit pre-sets a power grid strength threshold, which is defined based on a short circuit ratio (SCR) and used to measure the power grid bearing capacity and stability of the grid-connected point. When the real-time SCR value monitored by the power grid state monitoring unit is lower than the pre-set power grid strength threshold, the system generates a control instruction to switch to the grid-constructing mode, so that the energy storage system is disconnected from the main power grid and independently runs; when the real-time SCR value is higher than the power grid strength threshold, the system generates a control instruction to switch to the grid-following mode, so that the energy storage system re-joins the power grid, thereby realizing optimal utilization of electric energy and stable support for the power grid. In addition, the cooperative control unit also has an online switching function. During the mode switching process, the output power of the energy storage unit is continuously monitored and the output curve is adjusted, so as to realize smooth transition of power and avoid sudden power fluctuations or grid disturbances during switching, thereby ensuring stable operation of the system in a dynamic power grid environment.

[0065] For example, the cooperative control unit intelligently judges and dynamically switches the operation mode of the grid-constructing energy storage system according to the real-time power grid operation parameters collected by the power grid state monitoring unit, so as to ensure safe, stable and efficient operation of the energy storage system under different power grid conditions. To achieve this goal, the cooperative control unit pre-sets a power grid strength threshold, which is defined based on a short circuit ratio (SCR) and used to evaluate the power grid bearing capacity and stability of the grid-connected point.

[0066] When the real-time SCR value detected by the power grid state monitoring unit is lower than the pre-set threshold, it indicates that the power grid bearing capacity is insufficient or there are potential instability factors, and the cooperative control unit generates a control instruction to switch to the grid-constructing mode, so that the energy storage system is disconnected from the main power grid and independently runs. In the grid-constructing mode, the power output of the energy storage system can be operated according to a pre-set strategy, so as to ensure the stability of the energy storage unit itself and prevent negative effects on the power grid. On the contrary, when the real-time SCR value is higher than the threshold, it indicates that the power grid strength is sufficient, and the system can be safely connected to the grid, at which time a control instruction is generated to switch to the grid-following mode, so that the energy storage system re-joins the power grid, thereby realizing optimal utilization of electric energy and stable support for the power grid. To more intuitively illustrate the mode switching and power output strategy, an example is shown in the following table:

[0067] During actual operation, the cooperative control unit continuously monitors the output power of the energy storage unit through the online switching function, and dynamically adjusts the power curve according to the mode switching requirements. This function can effectively eliminate the power mutation that may occur during the switching process, so that the switching between the grid-constructing mode and the grid-following mode is smooth and disturbance-free, thereby avoiding power grid frequency or voltage fluctuations caused by switching.

[0068] Furthermore, this embodiment can combine historical operating data with predictive analysis to intelligently judge the SCR change trend and adjust the energy storage system's output strategy in advance, improving the system's pre-adaptive capability to sudden grid disturbances. When the grid experiences significant fluctuations or a decrease in short-circuit capacity, the system can quickly switch to grid connection mode and adjust power output to ensure the safe operation of the energy storage unit while reducing the impact on the grid. When the grid stabilizes and the SCR value exceeds the threshold again, the system can automatically switch to grid-following mode and gradually increase power output according to dispatch instructions to achieve safe and smooth grid connection operation.

[0069] Through the above measures, this embodiment realizes the improvement of intelligent mode switching, power smooth transition and online response capabilities of grid-type energy storage system, effectively improving the safety, stability and reliability of energy storage system in complex power grid environment, while enhancing the adaptability to the access of new energy grid.

[0070] Specifically, the transient response execution unit includes: an inertia support module configured to simulate the inertial response of a synchronous generator based on the grid frequency change rate monitored by the grid status monitoring unit, providing virtual inertia support; the inertia time constant configured in the inertia support module is adjustable within the range of 0 to 20 seconds; a fault ride-through module configured to support the grid when the grid status monitoring unit detects a sudden change in grid voltage or phase angle; an oscillation suppression module configured to output damping control power to suppress power oscillation when the grid status monitoring unit detects a power oscillation of a specific frequency in the grid; and a black start support module configured to receive a black start command when a large-scale power outage occurs in the grid, provide voltage and frequency references for the grid and new energy power plants in the designated area, and execute the regional grid recovery process.

[0071] Specifically, when the grid state monitoring unit detects a sudden change in grid voltage or phase angle, the fault ride-through module provides the following grid support operations: Low-voltage fault ride-through operation: When the grid connection point voltage is detected to drop to within 0% to 90% of the rated voltage, the power conversion system (PCS) outputs reactive current within 10 milliseconds, and the reactive current fluctuation during low-voltage ride-through is less than 15%, the transient overvoltage caused after fault recovery is less than 10%, and it maintains strong overload support capability for at least 10 seconds; High-voltage fault ride-through operation: When the grid connection point voltage is detected to rise to within 110% to 130% of the rated voltage, the active power output remains unchanged within the full battery state of charge (SOC) range, achieving transient decoupling control of active and reactive power; Phase angle jump ride-through operation: When a step jump in the phase angle of the grid connection point voltage is detected, the amplitude and phase angle of the generator terminal voltage are kept stable, and active power is output to suppress grid phase angle jumps.

[0072] Specifically, when the power grid state monitoring unit detects that the power grid has power oscillation at a specific frequency, the oscillation suppression module outputs damping control power to suppress the power oscillation, and the oscillation suppression module is further configured to perform fast Fourier transform on the active power signal collected by the power grid state monitoring unit in real time, and determine whether there is a low-frequency oscillation component with a frequency in the range of 0.2 Hz to 2.5 Hz, wherein: if the low-frequency oscillation component is identified and its amplitude exceeds a preset oscillation threshold, a modulated active power signal with a controlled amplitude and opposite phase to the oscillation component is determined; the oscillation suppression module is further configured to superimpose the modulated active power signal on the active component of the power scheduling instruction output by the cooperative control unit, and based on the power conversion system PCS output to the power grid, the maximum variation of the modulated active power signal is in the range of 10% to 30% of the rated power of the energy storage system.

[0073] Specifically, when the black start support module executes the recovery process of the regional power grid, the black start support module is further configured to disconnect the connection with the main power grid and enter the island operation mode after receiving the black start authorization instruction from the power grid dispatching center; the black start support module is further configured to control multiple power conversion systems PCS to operate in parallel, establish a stable voltage and frequency reference without external power grid support, and the number of PCSs operating in parallel is not less than 10, and the maximum deviation of the effective value of the current output by each PCS operating in parallel is not more than 5%; the black start support module is further configured to provide power supply for new energy stations, loads or synchronous generators in substations according to a preset black start path scheme configured by the black start support module.

[0074] It can be understood that the transient response execution unit realizes the rapid response and stable support of the network-constructed energy storage system under the grid disturbance, fault or large-scale power failure event through the cooperation of multiple modules. Its core includes inertia support module, fault ride-through module, oscillation suppression module and black start support module. Each module realizes dynamic adjustment and active protection through real-time monitoring of key grid parameters. Specifically, the inertia support module is used to simulate the inertia response of synchronous generators to provide virtual inertia support. When the grid state monitoring unit detects the grid frequency change rate, the inertia support module adjusts the output power of the energy storage system according to the change rate, thereby suppressing the frequency fluctuation. The inertia time constant of the module can be adjusted in the range of 0 seconds to 20 seconds to adapt to the dynamic demand under different grid conditions, realizing the rapid and stable response of the energy storage system to the grid frequency. Secondly, the fault ride-through module is used to deal with the sudden change of grid voltage or phase angle. In the low voltage fault ride-through operation, when the grid voltage drops to 0% to 90% of the rated voltage, the power conversion system (PCS) outputs reactive current within 10 milliseconds, ensures that the reactive current fluctuation is less than 15% during the ride-through period, and the transient overvoltage is less than 10% after fault recovery, and maintains strong overload support capability for at least 10 seconds. In the high voltage fault ride-through operation, when the voltage rises to 110% to 130% of the rated voltage, the PCS maintains the active power output unchanged within the full battery state of charge (SOC) range, realizing the transient decoupling control of active power and reactive power. In the phase angle jump ride-through operation, when the voltage phase angle jumps, the system maintains the stability of the machine terminal voltage amplitude and phase angle, and outputs active power to suppress the impact of sudden phase angle change of the grid on the system. In addition, the oscillation suppression module is used to deal with the specific frequency power oscillation existing in the grid. The module performs fast Fourier transform on the active power signal collected by the grid state monitoring unit in real time, identifies the low-frequency oscillation component with a frequency of 0.2 Hz to 2.5 Hz, and when the amplitude of the low-frequency oscillation component exceeds the preset threshold, the oscillation suppression module generates a modulated active power signal with opposite phase and controlled amplitude to the oscillation component, and superimposes it on the active component of the power scheduling instruction output by the cooperative control unit, and injects it into the grid through the PCS, realizing the suppression of power oscillation. The maximum change of the modulated power signal is controlled in the range of 10% to 30% of the rated power of the energy storage system, thereby balancing the response speed and system stability. Finally, the black start support module is used to restore the voltage and frequency reference of the grid and new energy station in a specified area when the grid experiences a large-scale power failure. After receiving the black start authorization instruction from the grid dispatching center, the module disconnects from the main grid and enters the island operation mode. The black start support module establishes a stable voltage and frequency reference by controlling multiple PCSs to operate in parallel, and the number of parallel PCSs is not less than 10, and the maximum deviation of the effective value of the output current of each PCS is not more than 5%.Subsequently, the module provides power supply for new energy station, substation load and synchronous generator in steps according to the preset black start path scheme, and realizes the gradual recovery of regional power grid. Through the synergistic effect of the four functional modules, the rapid response and steady-state support of the grid-structured energy storage system under complex conditions such as power grid frequency fluctuation, voltage mutation, power oscillation and large-area power failure are realized. Through real-time monitoring and dynamic adjustment of key grid parameters, each module not only provides virtual inertia support, fault ride-through protection, oscillation suppression and black start capability, but also ensures the high reliability and safety of the energy storage system and the stability of the overall operation of the power grid.

[0075] It can be seen that the transient response execution unit of the grid-structured energy storage power grid safety protection system includes inertia support module, fault ride-through module, oscillation suppression module and black start support module, and each module cooperates to realize the rapid response and steady-state support of the power grid disturbance and abnormal event. The implementation of each module is described below in combination with specific parameters and numerical examples.

[0076] The inertia support module simulates the inertia response of the synchronous generator according to the grid frequency change rate monitored by the grid state monitoring unit, and provides virtual inertia support for the power grid. The inertia time constant can be adjusted in the range of 0 seconds to 20 seconds, which can be flexibly set according to the degree of grid fluctuation to realize the rapid dynamic response of the energy storage system to the grid frequency. For example, when the frequency drop rate exceeds 0.1 Hz / s, the module automatically adjusts the PCS output power to increase the inertia support and stabilize the grid frequency. The fault ride-through module is used to support operation when the grid voltage or phase angle changes, including low voltage fault ride-through, high voltage fault ride-through and phase angle jump ride-through. The specific implementation examples are as follows:

[0077]

[0078] The oscillation suppression module is used to suppress the low-frequency power oscillation of 0.2 Hz to 2.5 Hz in the power grid. The specific implementation includes fast Fourier transform (FFT) analysis of the real-time active power signal, identification of the oscillation component, and generation of a modulated active power signal with controlled amplitude and opposite phase, which is superimposed into the power scheduling instruction. The maximum variation of the modulated signal is controlled within 10%-30% of the rated power of the energy storage system, thereby effectively suppressing the power oscillation of the power grid.

[0079] The black start support module is used to restore the regional power grid in the event of a large-scale power failure. The implementation steps include: receiving the black start authorization instruction of the power grid dispatching center, disconnecting the connection with the main power grid, and entering the island operation mode; controlling multiple PCSs to operate in parallel to establish a stable voltage and frequency reference, and the number of parallel PCSs is ≥10, and the maximum deviation of the effective value of the output current of each PCS is ≤5%; according to the preset black start path scheme, power supply is provided for new energy stations, substation loads or synchronous generators in steps, and regional power grid restoration is realized.

[0080] The following table is an implementation example of the black start support module:

[0081]

[0082] Through the above embodiments, each module realizes dynamic stability control and safety support of the energy storage system under different power grid disturbance conditions through real-time monitoring and rapid response of power grid frequency, voltage and phase angle. Combined with inertia support, fault ride-through, oscillation suppression and black start support, the transient response execution unit can effectively improve the anti-disturbance ability and reliability of the grid-forming energy storage power grid.

[0083] Specifically, when the digital and intelligent safety protection unit performs full-state monitoring and active protection on the physical environment safety, network information safety and equipment operation safety of the grid-forming energy storage system, it includes: the digital and intelligent safety protection unit is also configured to collect environmental data of the location of the energy storage equipment, wherein the environmental data includes wind speed, dust concentration and temperature; the digital and intelligent safety protection unit is also configured to perform linkage operations including adjusting the equipment cooling strategy and reinforcing the external protection structure when the environmental data exceeds the preset safety threshold configured by the digital and intelligent safety protection unit; the digital and intelligent safety protection unit is also configured to verify the localization information of the core hardware and software components of the grid-forming energy storage system, wherein the core hardware and software components include insulated gate bipolar transistors (IGBT), control chips and operating systems; wherein the verification is based on the built-in self-controllable component database; the digital and intelligent safety protection unit is also configured to monitor the operating state of the energy storage system in the full state of charge (SOC) range, low short circuit capacity ratio and high voltage disturbance working conditions, and execute active control strategies to ensure that the active power does not decrease during high voltage ride-through, and to realize full power stable operation under the condition of weak power grid with short circuit capacity ratio (SCR) of 1.1.

[0084] In particular, the digitalized safety protection unit further includes: the digitalized safety protection unit is further configured to monitor internal state parameters of each battery pack in the energy storage system, the internal state parameters including temperature, voltage, and internal resistance; and the digitalized safety protection unit is further configured to perform a fire suppression operation on any battery pack when an internal state parameter of the battery pack exceeds a fire warning threshold configured by the digitalized safety protection unit.

[0085] In particular, the digitalized safety protection unit further includes an overload operation capability, which is specifically: when the rated current is 110%, the digitalized safety protection unit determines not to adjust the operation time; when the rated current is 120%, the digitalized safety protection unit determines that the operation time is not less than 2 minutes; and when a serious fault occurs in the power grid, the digitalized safety protection unit has a short-time overload capability of outputting 300% of the rated current, and the operation time is 10 seconds.

[0086] It can be understood that the digital security protection unit realizes the reliability and safety of the energy storage system under complex operating conditions by monitoring and actively protecting the physical environment safety, network information safety and equipment operation safety of the network-constructed energy storage system. First, the digital security protection unit collects real-time environmental data of the location of the energy storage equipment, including wind speed, dust concentration and temperature, and other key parameters. When the collected environmental data exceeds the preset safety threshold, the system automatically performs linkage operations, such as adjusting the equipment cooling strategy, reinforcing the external protection structure, etc., to ensure that the energy storage equipment can still operate stably under extreme environmental conditions, avoiding equipment damage or performance degradation caused by environmental factors. Second, the digital security protection unit checks the localization information of the key components of the network-constructed energy storage system, including IGBT, control chip and operating system, through the built-in autonomous controllable component database. This checking mechanism ensures that the key components of the system are controllable, reduces the security risks caused by unreliable hardware and software or external supply chain risks, and thus strengthens the network information safety and operation safety of the energy storage system. At the same time, the digital security protection unit can monitor the operating state of the energy storage system under full state of charge (SOC range), low short circuit capacity ratio (SCR) and high voltage disturbance conditions, and execute active control strategies. For example, during high voltage ride-through, the system ensures that the active power is not reduced in output; under weak grid conditions (SCR is 1.1), the system can still realize stable operation of the energy storage unit at full power. This active control strategy ensures the operating stability and grid support capability of the energy storage system under different grid conditions through real-time feedback and dynamic adjustment. In addition, the digital security protection unit also monitors the internal state parameters of each battery pack in the energy storage system, including temperature, voltage and internal resistance. When the parameters of any battery pack exceed the fire warning threshold, the system will immediately execute fire suppression operations for that battery pack, such as starting the fire extinguishing device or isolating the faulty battery, to prevent battery thermal runaway and fire accidents. Finally, the digital security protection unit has overload operation capability and can maintain the safe operation of the energy storage system under different overload conditions. For example, when the energy storage system operates at 110% rated current, the system does not need to adjust the operating time; at 120% rated current, the operating time remains no less than 2 minutes; during the transient state of serious grid failure, the system can output 300% rated current for a short time, with a duration of 10 seconds, to ensure that the energy storage system can still complete the grid support task under extreme load conditions. Through these measures, the digital security protection unit realizes comprehensive monitoring and active protection of the environment, hardware, operation and grid conditions of the energy storage system, thereby significantly improving the safety, reliability and adaptability of the network-constructed energy storage grid.

[0087] As can be seen, the digital security protection unit first collects environmental data of the energy storage device location through the environmental monitoring module, including wind speed, sand concentration and temperature. When the collected environmental data exceeds the preset safety threshold, the system will perform a linkage protection operation, such as adjusting the device cooling strategy or reinforcing the external protection structure, to ensure the reliable operation of the device in extreme environments. The digital security protection unit also checks the core hardware and software components of the networked energy storage system through the built-in autonomous controllable component database, including IGBT, control chip and operating system, to ensure that the core components are controllable and reduce the risk of external supply chain. The system also monitors the operating state of the energy storage system in the full SOC range, low short-circuit capacity ratio and high voltage disturbance working condition, and executes the active control strategy to ensure that the active power is not reduced during high voltage crossing, while achieving full power stable operation of the energy storage unit under weak grid conditions (SCR is 1.1). At the same time, the digital security protection unit monitors the internal state parameters of each battery pack, including temperature, voltage and internal resistance. When any battery pack parameter exceeds the fire warning threshold, the system will automatically execute the fire suppression operation for the battery pack, such as starting the fire extinguishing device or isolating the faulty battery, to prevent battery thermal runaway and fire accidents.

[0088] In addition, the digital security protection unit has overload running capability, and its running strategy is shown in the following table:

[0089]

[0090] Through the above design, the digital security protection unit of the present embodiment can realize all-round monitoring and active protection of the energy storage system under various complex environments and grid conditions, including environmental safety, device safety, operating state and grid support capability, thereby improving the safety, stability and reliability of the networked energy storage system.

[0091] In the above embodiment, the grid state monitoring unit collects key operating parameters of the grid-connected point of the grid-constructing energy storage system in real time, including grid voltage, grid frequency, short circuit capacity ratio (SCR), and phase angle, etc. information, to realize comprehensive control of the grid operating state, and provide accurate and real-time data basis for the operation and regulation of the energy storage system. Through continuous monitoring of the grid state, problems such as grid fluctuation, frequency anomaly or short circuit capacity change can be found in time, providing a basis for subsequent collaborative control and transient response, so as to effectively avoid the failure of regulation caused by information lag or inaccurate data. Secondly, the collaborative control unit can generate operating mode control instructions and power scheduling instructions based on the preset Shaguo Huang new energy base operating strategy model, to realize dynamic switching between grid-constructing mode and grid-following mode. This switching not only meets the flexible demand under different grid operating conditions, but also coordinates the execution of primary frequency modulation instructions, automatic generation control (AGC) instructions and automatic voltage control (AVC) instructions, realizes multi-dimensional power scheduling collaborative management, significantly improves the regulation efficiency and grid support capability of the energy storage system, and effectively alleviates the instability factors caused by new energy generation fluctuation. At the same time, when receiving the collaborative control instructions or monitoring the grid disturbance, the transient response execution unit can quickly execute multi-dimensional transient response operations such as power rapid adjustment, operating mode switching and local load regulation, so as to maintain the stability of the grid-connected point voltage and frequency. This rapid response capability can significantly improve the dynamic stability of the system in the face of grid disturbance or sudden abnormal events, reduce the impact on the grid, and improve the adaptability of the energy storage unit to grid fluctuations. Finally, the digital security protection unit realizes full-state monitoring and active protection of the physical environment safety, network information safety and equipment operation safety of the grid-constructing energy storage system, effectively reducing the influence of external attacks or internal faults on the system operation. The unit can realize abnormal detection, intrusion warning, fault isolation and risk assessment of key equipment of the energy storage system, ensure the long-term stable operation of the energy storage system, and provide reliable security protection for the grid.

[0092] In another preferred mode based on the above embodiment, as shown in Figure 3 the present embodiment provides a grid-constructing energy storage grid safety protection method, comprising:

[0093] Step S100, real-time collection of grid operating parameters of the grid-connected point of the grid-constructing energy storage system, the grid operating parameters including grid voltage, grid frequency, short circuit capacity ratio SCR and phase angle.

[0094] Step S200, receiving power grid operation parameters, and generating a coordinated control instruction based on a preset Shaguo Barren New Energy Base operation strategy model, the coordinated control instruction including an operation mode control instruction and a power scheduling instruction; the operation mode control instruction is used for switching between a grid-connected mode and a grid-following mode, and the power scheduling instruction includes a primary frequency modulation instruction, an automatic generation control (AGC) instruction and an automatic voltage control (AVC) instruction.

[0095] Step S300, when the coordinated control instruction is received or the power grid disturbance is monitored, performing a multi-dimensional transient response operation to maintain the stability of the grid-connected point voltage and frequency.

[0096] Step S400, performing full-state monitoring and active protection on the physical environment safety, network information safety and equipment operation safety of the grid-connected type energy storage system.

[0097] It can be understood that the grid-connected type energy storage grid safety protection system and method in each of the above embodiments of the present application have the same beneficial effects, which will not be described again.

[0098] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0099] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams can be implemented by computer program instructions, and the combination of flows and / or blocks in the flowcharts and / or block diagrams. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks.

[0100] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction devices, which implement the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1the function specified in the one or more blocks.

[0101] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, so that the instructions executed on the computer or other programmable devices provide processes for implementing the flowcharts Figure 1 one or more flows and / or blocks Figure 1 the steps of the function specified in the one or more blocks.

[0102] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the above embodiments of the present application have been described in detail, those skilled in the art should understand: the specific embodiments of the present application can be modified or replaced by the same, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered within the scope of protection of the claims of the present application.

Claims

1. A grid-based energy storage power grid security protection system, characterized in that, include: The power grid status monitoring unit is used to collect real-time power grid operating parameters at the grid connection point of the grid-connected energy storage system. These parameters include grid voltage, grid frequency, short-circuit capacity ratio (SCR), and phase angle. The collaborative control unit is used to receive grid operation parameters and generate collaborative control commands based on the preset operation strategy model of the Shagohuang New Energy Base. The collaborative control commands include operation mode control commands and power dispatch commands. The operation mode control commands are used to switch between grid-connected mode and grid-following mode. The power dispatch commands include primary frequency regulation commands, automatic generation control (AGC) commands, and automatic voltage control (AVC) commands. The transient response execution unit is used to perform multi-dimensional transient response operations when receiving coordinated control commands or detecting grid disturbances, in order to maintain the stability of voltage and frequency at the grid connection point; The digital security protection unit is used to perform full-state monitoring and proactive protection of the physical environment security, network information security and equipment operation security of grid-type energy storage systems.

2. The grid-type energy storage power grid security protection system according to claim 1, characterized in that, When the cooperative control unit generates operating mode control commands, it includes: The cooperative control unit is also configured to preset a grid strength threshold, which is defined based on the short-circuit capacity ratio (SCR). When the real-time SCR value detected by the power grid status monitoring unit is lower than the power grid strength threshold, the collaborative control unit generates a control command to switch to the grid construction mode. When the real-time SCR value is higher than the grid strength threshold, the collaborative control unit generates a control command to switch to grid-following mode; The collaborative control unit is also used to perform online switching functions to ensure a smooth transition of power output and grid connection without disturbance during mode switching.

3. The grid-type energy storage power grid security protection system according to claim 1, characterized in that, The transient response execution unit includes: The inertia support module is configured to simulate the inertial response of the synchronous generator based on the grid frequency change rate monitored by the grid status monitoring unit, and provide virtual inertia support; the inertia time constant configured in the inertia support module is adjustable within the range of 0 seconds to 20 seconds; The fault ride-through module is configured to support grid operations when the grid condition monitoring unit detects a sudden change in grid voltage or phase angle. The oscillation suppression module is configured to output damping control power to suppress power oscillations when the power grid condition monitoring unit detects power oscillations of a specific frequency in the power grid. The black start support module is configured to receive black start commands when a large-scale power outage occurs in the power grid, provide voltage and frequency references for the power grid and new energy power plants in the designated area, and execute the regional power grid restoration process.

4. The grid-type energy storage power grid security protection system according to claim 3, characterized in that, When the grid condition monitoring unit detects a sudden change in grid voltage or phase angle, the fault ride-through module provides the following grid support operations: Low voltage fault ride-through operation: When the grid connection point voltage is detected to drop to the range of 0% to 90% of the rated voltage, the control power conversion system PCS outputs reactive current within 10 milliseconds, and the reactive current fluctuation during the low voltage ride-through is less than 15%, the transient overvoltage caused after the fault is recovered is less than 10%, and it maintains strong overload support capability for at least 10 seconds. High-voltage fault ride-through operation: When the grid connection point voltage is detected to rise to 110% to 130% of the rated voltage, the active power output remains unchanged within the full battery state of charge (SOC) range, achieving transient decoupling control of active and reactive power. Phase angle jump ride-through operation: When a step jump in the phase angle of the grid connection point voltage is detected, the generator terminal voltage amplitude and phase angle are kept stable, and active power is output to suppress the grid phase angle jump.

5. The grid-type energy storage power grid security protection system according to claim 3, characterized in that, When the power grid condition monitoring unit detects power oscillations of a specific frequency in the power grid, the oscillation suppression module outputs damping control power to suppress the power oscillations, including: The oscillation suppression module is also configured to perform a fast Fourier transform on the active power signal acquired by the power grid condition monitoring unit in real time to determine whether there are low-frequency oscillation components in the range of 0.2 Hz to 2.5 Hz, wherein: If a low-frequency oscillation component is identified and its amplitude exceeds a preset oscillation threshold, then a modulated active power signal with a phase opposite to the oscillation component and controlled amplitude is determined. The oscillation suppression module is also configured to superimpose the modulated active power signal onto the active component of the power dispatch command output by the coordinating control unit, and output to the grid based on the power conversion system PCS. The maximum value of the variation of the modulated active power signal is within the range of 10% to 30% of the rated power of the energy storage system.

6. The grid-type energy storage power grid security protection system according to claim 3, characterized in that, When the black start support module executes the regional power grid restoration process, it includes: The black start support module is also configured to disconnect from the main power grid and enter islanded operation mode after receiving a black start authorization command from the power grid dispatch center; The black start support module is also configured to control multiple power conversion system PCS to operate in parallel, establish a stable voltage and frequency reference without external power grid support, and have no less than 10 PCS operating in parallel, and the maximum deviation of the effective value of the current output by each PCS during parallel operation is no more than 5%. The black start support module is also configured to provide power to loads or synchronous generators in new energy power plants and substations in stages according to the preset black start path scheme configured by the black start support module.

7. The grid-type energy storage power grid security protection system according to claim 1, characterized in that, When the intelligent digital security protection unit performs full-state monitoring and proactive protection of the physical environment security, network information security, and equipment operation security of a grid-type energy storage system, it includes: The intelligent security protection unit is also configured to collect environmental data of the location of the energy storage device, including wind speed, dust concentration and temperature; The intelligent security protection unit is also configured to perform coordinated operations, including adjusting the device's heat dissipation strategy and reinforcing the external protection structure, when environmental data exceeds the preset security threshold configured by the intelligent security protection unit. The digital security protection unit is also configured to verify the localization information of the core hardware and software components of the grid-type energy storage system. The core hardware and software components include insulated gate bipolar transistors (IGBTs), control chips, and operating systems. The verification is based on a built-in database of independently controllable components. The intelligent safety protection unit is also configured to monitor the operating status of the energy storage system under full state of charge (SOC) range, low short-circuit capacity ratio (SCR), and high voltage disturbance conditions, and to execute active control strategies to ensure that active power is not derated during high voltage ride-through and to achieve full-power stable operation under weak grid conditions with a short-circuit capacity ratio (SCR) of 1.

1.

8. The grid-type energy storage power grid security protection system according to claim 7, characterized in that, The intelligent security protection unit also includes the following when performing full-state monitoring and active protection of the physical environment security, network information security and equipment operation security of grid-type energy storage systems: The intelligent security protection unit is also configured to monitor the internal status parameters of each battery pack in the energy storage system, including temperature, voltage and internal resistance. The intelligent safety protection unit is also configured to perform fire suppression operation on any battery pack when the internal state parameters of any battery pack exceed the fire warning threshold configured by the intelligent safety protection unit.

9. The grid-type energy storage power grid security protection system according to claim 8, characterized in that, The intelligent security protection unit is also equipped with overload operation capability, which specifically includes: When operating at 110% of the rated current, the intelligent safety protection unit determines that the running time will not be adjusted; Under 120% rated current conditions, the intelligent safety protection unit is required to operate for no less than 2 minutes. During a transient period of severe power grid failure, it has the short-term overload capability to output 300% of the rated current, and the intelligent safety protection unit determines the operating time to be 10 seconds.

10. A method for security protection of a grid-type energy storage power grid, applied to the security protection system of a grid-type energy storage power grid as described in any one of claims 1-9, characterized in that, include: Real-time acquisition of grid operation parameters at the grid connection point of the grid-connected energy storage system. Grid operation parameters include grid voltage, grid frequency, short-circuit capacity ratio (SCR), and phase angle. It receives grid operation parameters and generates coordinated control commands based on the preset operation strategy model of the Shagohuang New Energy Base. The coordinated control commands include operation mode control commands and power dispatch commands. The operation mode control commands are used to switch between grid-connected mode and grid-following mode. The power dispatch commands include primary frequency regulation commands, automatic generation control (AGC) commands, and automatic voltage control (AVC) commands. Upon receiving a coordinated control command or detecting grid disturbances, perform multi-dimensional transient response operations to maintain the stability of voltage and frequency at the grid connection point; Full-state monitoring and proactive protection are implemented for the physical environment security, network information security, and equipment operation security of grid-type energy storage systems.

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